An exception occured while creating a query in EntityManager

Question

I was directed to create a new topic rather than resurrect a long dead thread. I appreciate the correction in this.
Persistence, Entity Manager, NetBeans 6.7.1, GlassFish v2.1, Database
I am getting the following Stack Trace:
[#|2009-12-08T16:22:06.171-0500|SEVERE|sun-appserver2.1|javax.faces|_ThreadID=18;_ThreadName=httpSSLWorkerThread-8080-1;_RequestID=390db479-49c0-47e5-bcdc-e5e07f871644;|javax.faces.event.AbortProcessingException: java.lang.IllegalArgumentException: An exception occured while creating a query in EntityManager
javax.faces.event.AbortProcessingException: java.lang.IllegalArgumentException: An exception occured while creating a query in EntityManager
     at javax.faces.event.MethodExpressionValueChangeListener.processValueChange(MethodExpressionValueChangeListener.java:82)
     at javax.faces.event.ValueChangeEvent.processListener(ValueChangeEvent.java:123)
     at javax.faces.component.UIComponentBase.broadcast(UIComponentBase.java:746)
     at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:416)
     at sun.reflect.GeneratedMethodAccessor290.invoke(Unknown Source)
     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
     at java.lang.reflect.Method.invoke(Method.java:597)
     at com.sun.faces.extensions.avatar.components.PartialTraversalViewRootHelper.broadcastEvents(PartialTraversalViewRootHelper.java:500)
     at com.sun.faces.extensions.avatar.components.PartialTraversalViewRootHelper.processValidators(PartialTraversalViewRootHelper.java:267)
     at com.sun.faces.extensions.avatar.components.PartialTraversalViewRootImpl.processValidators(PartialTraversalViewRootImpl.java:152)
     at com.sun.faces.lifecycle.ProcessValidationsPhase.execute(ProcessValidationsPhase.java:100)
     at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:251)
     at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:117)
     at com.sun.faces.extensions.avatar.lifecycle.PartialTraversalLifecycle.execute(PartialTraversalLifecycle.java:94)
     at javax.faces.webapp.FacesServlet.service(FacesServlet.java:244)
     at org.apache.catalina.core.ApplicationFilterChain.servletService(ApplicationFilterChain.java:427)
     at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:315)
     at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:287)
     at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:218)
     at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:648)
     at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:593)
     at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:94)
     at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:98)
     at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:222)
     at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:648)
     at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:593)
     at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:587)
     at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:1096)
     at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:166)
     at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:648)
     at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:593)
     at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:587)
     at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:1096)
     at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:288)
     at com.sun.enterprise.web.connector.grizzly.DefaultProcessorTask.invokeAdapter(DefaultProcessorTask.java:647)
     at com.sun.enterprise.web.connector.grizzly.comet.CometEngine.executeServlet(CometEngine.java:609)
     at com.sun.enterprise.web.connector.grizzly.comet.CometEngine.handle(CometEngine.java:356)
     at com.sun.enterprise.web.connector.grizzly.comet.CometAsyncFilter.doFilter(CometAsyncFilter.java:84)
     at com.sun.enterprise.web.connector.grizzly.async.DefaultAsyncExecutor.invokeFilters(DefaultAsyncExecutor.java:175)
     at com.sun.enterprise.web.connector.grizzly.async.DefaultAsyncExecutor.interrupt(DefaultAsyncExecutor.java:153)
     at com.sun.enterprise.web.connector.grizzly.async.AsyncProcessorTask.doTask(AsyncProcessorTask.java:92)
     at com.sun.enterprise.web.connector.grizzly.TaskBase.run(TaskBase.java:265)
     at com.sun.enterprise.web.connector.grizzly.ssl.SSLWorkerThread.run(SSLWorkerThread.java:106)
Caused by: java.lang.IllegalArgumentException: An exception occured while creating a query in EntityManager
     at oracle.toplink.essentials.internal.ejb.cmp3.EntityManagerImpl.createQuery(EntityManagerImpl.java:209)
     at com.davisco.web.jpa.controllers.EmpdataJpaController.findEmpdataEntities(EmpdataJpaController.java:165)
     at com.davisco.web.jpa.controllers.EmpdataJpaJpaController.findEmpdataJpaEntities(EmpdataJpaJpaController.java:155)
     at com.davisco.web.jpa.controllers.EmpdataJpaJpaController.findEmpdataJpaEmpnoEntities(EmpdataJpaJpaController.java:214)
     at com.davisco.web.jsf.EmpdataController.getEmployeesByEmpno(EmpdataController.java:471)
     at com.davisco.web.jsf.EmpdataController.addEmployeeEmpnos(EmpdataController.java:439)
     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
     ... 48 more
Caused by: Exception [TOPLINK-8034] (Oracle TopLink Essentials - 2.1 (Build b60e-fcs (12/23/2008))): oracle.toplink.essentials.exceptions.EJBQLException
Exception Description: Error compiling the query [select object(o) from Empdata as o]. Unknown abstract schema type [Empdata].
     at oracle.toplink.essentials.exceptions.EJBQLException.unknownAbstractSchemaType(EJBQLException.java:494)
     at oracle.toplink.essentials.internal.parsing.ParseTreeContext.classForSchemaName(ParseTreeContext.java:163)
     at oracle.toplink.essentials.internal.parsing.SelectNode.getClassOfFirstVariable(SelectNode.java:366)
     at oracle.toplink.essentials.internal.parsing.SelectNode.getReferenceClass(SelectNode.java:354)
     ... 65 more
It appears that problem
|javax.faces.event.AbortProcessingException: java.lang.IllegalArgumentException: An exception occured while creating a query in EntityManager
is actually caused by
Exception Description: Error compiling the query [select object(o) from Empdata as o]. Unknown abstract schema type [Empdata].
The Query is a very basic query.
     private EntityManagerFactory emf = javax.persistence.Persistence.createEntityManagerFactory("PersistPU");
     public EntityManager getEntityManager() {
          return emf.createEntityManager();
     private List<Empdata> findEmpdataEntities(boolean all, int maxResults, int firstResult) {
          EntityManager em = getEntityManager();
          try {
               Query q = em.createQuery("select object(o) from Empdata as o"); // Problem line
               if (!all) {
                    q.setMaxResults(maxResults);
                    q.setFirstResult(firstResult);
               return q.getResultList();
          } finally {
               em.close();
I have reviewed my Configuration Files and Source Packages without solution.
Where do I need to look or what do I need to do to determine the error?

Answer 1

After reading similar discussion in the OTN Discussion page ( [Thread: Unknown abstract schema type |http://forums.oracle.com/forums/thread.jspa?threadID=602826] ) I reviewed how I was creating my EntityManagerFactory. I realize also more information is required for a more complete understanding of the circumstances.
I originally created a project in Netbeans using the wizard to create a JSF Project from Entity Classes. Through trial and error I produced from the resulting JSF Web pages a maintenance project for a given table in the database. I was then given the task to split the table and build a new project utilizing the existing entity classes in a production project.
After the table was split and the new entity classes created I then entered the task of starting a new project using the entity classes in the production project. To do this I used the Netbeans wizard to create the JpaControllers in the production project. I copied as much code as I could from the working table maintenance project I had just completed. I have now started to connect the two projects. I have included the production project with the entities as a library project. I created the persistence.xml file in the new project with the same persistence unit name as the production project. I have included the Toplink Extensions as a library in the new project (even though the production project has the entity classes). From what I have been able to glean I am thinking my EntityManagerFactory declaration may be misdirecting the finding of the Empdata schema in my new project. Here is how I declared my EntityManager in the example given:
private EntityManagerFactory emf = javax.persistence.Persistence.createEntityManagerFactory("DvPersistPU");
     public EntityManager getEntityManager() {
          return emf.createEntityManager();
Here is the wizard generated method which fails with a NullPointerException in the return statement:
     @PersistenceUnit(unitName = "PersistPU")
     private EntityManagerFactory emf = null;
     public EntityManager getEntityManager() {
          return emf.createEntityManager();
Hopefully this will better help someone to direct me to determining the cause of my error or the error of my ways.
NullPointerException stacktrace just mentioned:
EmpdataController: getEmployeesByEmpno [0]
AbortProcessingException thrown when processing event of type 'javax.faces.event.ValueChangeEvent' during phase 'PROCESS_VALIDATIONS 3' for component with ID or Client ID of 'srchEmp'
javax.faces.event.AbortProcessingException: java.lang.NullPointerException
javax.faces.event.AbortProcessingException: java.lang.NullPointerException
at javax.faces.event.MethodExpressionValueChangeListener.processValueChange(MethodExpressionValueChangeListener.java:82)
at javax.faces.event.ValueChangeEvent.processListener(ValueChangeEvent.java:123)
at javax.faces.component.UIComponentBase.broadcast(UIComponentBase.java:746)
at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:416)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.sun.faces.extensions.avatar.components.PartialTraversalViewRootHelper.broadcastEvents(PartialTraversalViewRootHelper.java:500)
at com.sun.faces.extensions.avatar.components.PartialTraversalViewRootHelper.processValidators(PartialTraversalViewRootHelper.java:267)
at com.sun.faces.extensions.avatar.components.PartialTraversalViewRootImpl.processValidators(PartialTraversalViewRootImpl.java:152)
at com.sun.faces.lifecycle.ProcessValidationsPhase.execute(ProcessValidationsPhase.java:100)
at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:251)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:117)
at com.sun.faces.extensions.avatar.lifecycle.PartialTraversalLifecycle.execute(PartialTraversalLifecycle.java:94)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:244)
Caused by: java.lang.NullPointerException
at com.company.web.jpa.controllers.EmpdataJpaController.getEntityManager(EmpdataJpaController.java:71)
at com.company.web.jpa.controllers.EmpdataJpaController.findEmpdataEntities(EmpdataJpaController.java:163)
at com.company.web.jpa.controllers.EmpdataJpaController.findEmpdataEntities(EmpdataJpaController.java:155)
at com.company.web.jpa.controllers.EmpdataJpaController.findEmpdataEmpnoEntities(EmpdataJpaController.java:214)
at com.company.web.jsf.EmpdataController.getEmployeesByEmpno(EmpdataController.java:471)
at com.company.web.jsf.EmpdataController.addEmployeeEmpnos(EmpdataController.java:439)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
... 49 more
Would someone please help me know where to look next or point me in the direction to find the cause of the error(s)?
Thank you.